Impact of Biochar and Bioorganic Fertilizer on Rhizosphere Bacteria in Saline–Alkali Soil

Abstract

Biochar and bioorganic fertilizers (BOF) that are used in agriculture can, both directly and indirectly, impact rhizosphere soil microorganisms. However, changes to the halophyte rhizosphere bacterial community after applying biochar and BOF to saline–alkali soil have not been thoroughly described. This study has investigated the bacterial communities of halophytes in saline–alkali soil through the addition of different biochar and BOF formulas using Illumina-based sequencing of the 16S rRNA gene fragment. B_BOF (biochar and BOF combined application) had the best effect, either by promoting the plant growth or by improving the physical and chemical properties of the soil. The concentration of the rhizosphere bacterial communities correlated with the changes in soil organic matter (OM) and organic carbon (OC). Proteobacteria, Actinobacteria, Chloroflexi, and Acidobacteria accounted for >80% of the total bacteria in each treatment. In addition, the abundance of Micromonospora was much higher in response to B_BOF than to the other treatments. BOF, with or without biochar, significantly influenced the bacterial community composition in the saline–alkali soil. The OC, OM, total nitrogen, and the available phosphorus had significant effects on the bacterial structure of this soil. The complex correlation of the bacterial communities between CK and B_BOF was higher compared to that between CK and FB or between CK and BOF. These findings suggested that the plant growth, the soil characteristics, and the diversity or community composition of the rhizosphere bacteria in saline–alkali soil were significantly influenced by B_BOF, followed by BOF, and then biochar; fine biochar had a stronger effect than medium or coarse biochar. This study provides an insight into the complex microbial compositions that emerge in response to biochar and BOF.

Effects of biochar amendment and organic fertilizer on microbial communities in the rhizosphere soil of wheat in Yellow River Delta saline-alkaline soil

“…Although many researches have explored the effects of biochar and organic fertilizer in agricultural fields, only a few have conducted saline–alkali field experiments ( Yao et al, 2017 ; Gu et al, 2022a , 2022b , 2023 ). Biochar amendment and application of organic fertilizer generally changes soil quality, such as pH, soil organic carbon, and nutrient content ( Lehmann et al, 2011 ; Luo et al, 2014 ; Yao et al, 2017 ).…”

“…Other field management followed local management practice. At the end of the field trial, wheat rhizosphere soil was obtained from the tilled area (0–20 cm) and collected and processed according to Gu et al (2022a) . Then, the collected samples were split into two parts: one for high-throughput sequencing, the other for soil physicochemical properties after being air-dried to remove impurities.…”

Effects of brackish water irrigation and biochar application on fertility, enzyme activity, and winter wheat yield in coastal saline‐alkali soils

“…The results indicated that biochar increased soil organic matter, nitrate nitrogen, and quick‐acting phosphorus, thereby improving the physicochemical and biological properties of the saline‐alkali soils and promoting crop growth. In Gu et al (2022) study, the synergistic use of biochar and bioorganic fertilizer proved beneficial. It led to improved soil physicochemical properties, increased inter‐root bacterial diversity, and positively influenced plant growth.…”

Soil fungal community is more sensitive than bacterial community to modified materials application in saline–alkali land of Hetao Plain

“…A recent study by Zhang et al (2022) revealed that long-term organic fertilizer application facilitates the proliferation of plant growth-promoting bacteria groups, such as Thiobacillus, Methylobacter, Rhodoferax, Lysobacter, and Flavobacterium, while the abundance of the halophilic genera was significantly decreased. Soil ameliorants, consisting of beneficial functional microbes (PGPR) along with a suitable substrate, are a specialized type of fertilizer that not only improve the soil physicochemical properties and enhance nutrient supply capacity but also alter the soil microbial community ( Lu et al, 2020 ; Gu et al, 2022 ; Huang J. et al, 2023 ). Numerous studies have provided evidence that soil ameliorant application can serve as an effective strategy for improving soil properties ( Naher et al, 2021 ), promoting soil microbial activities that are closely associated with nutrient cycling and disease resistance ( Lu et al, 2020 ; Huang B. et al, 2023 ), and enhancing soil fertility in a saline–alkali ecosystem ( Chen et al, 2021 ).…”